```Faster version of liberty_float - gives a 25% to 50% speedup

This also fixes a bug in liberty_float for numbers with a magnitute
between 9 and 15.

Previously:
>>> liberty_float(1e15)
'1000000000000000'
>>> liberty_float(1e10)
'10000000000.'
>>> liberty_float(1e9)
'1000000000.0'
>>> liberty_float(1e16)
'1.000000e+16'

Now:
>>> liberty_float(1e15)
'1.000000e+15'
>>> liberty_float(1e10)
'1.000000e+10'
>>> liberty_float(1e9)
'1000000000.0'
>>> liberty_float(1e16)
'1.000000e+16'
```
```diff --git a/scripts/python-skywater-pdk/skywater_pdk/liberty.py b/scripts/python-skywater-pdk/skywater_pdk/liberty.py
index 6cbda80..b14ec3e 100755
--- a/scripts/python-skywater-pdk/skywater_pdk/liberty.py
+++ b/scripts/python-skywater-pdk/skywater_pdk/liberty.py
```
```@@ -31,12 +31,15 @@

from typing import Tuple, List, Dict

+from math import frexp, log2
+
from . import sizes
from .utils import sortable_extracted_numbers

debug = False

+LOG2_10 = log2(10)

class TimingType(enum.IntFlag):
"""
@@ -792,36 +795,25 @@

"""
try:
-        f2 = float(f)
+        r = float(f)
except (ValueError, TypeError):
-        f2 = None
+        r = None

if isinstance(f, bool):
-        f2 = None
+        r = None

-    if f is None or f2 != f:
+    if f is None or r != f:
raise ValueError("%r is not a float" % f)

-    WIDTH = len(str(0.0083333333))
+    width = 11

-    s = json.dumps(f)
-    if 'e' in s:
-        a, b = s.split('e')
-        if '.' not in a:
-            a += '.'
-        while len(a)+len(b)+1 < WIDTH:
-            a += '0'
-        s = "%se%s" % (a, b)
-    elif '.' in s:
-        while len(s) < WIDTH:
-            s += '0'
+    mag = int(frexp(r)[1]/LOG2_10)
+    if mag > 9:
+        return f'%{width}e' % r
+    if mag < 0:
+        return f"%{width+1}.{width-1}f" % r
else:
-        if len(s) < WIDTH:
-            s += '.'
-        while len(s) < WIDTH:
-            s += '0'
-    return s
-
+        return f"%{width+1}.{width-mag-1}f" % r

LIBERTY_ATTRIBUTE_TYPES = {
'boolean':  liberty_bool,
```